Agilent/Keysight N4877A

The Agilent/Keysight N4877A is a clock data recovery and demultiplexer module for high-speed digital communication testing from 50 Mb/s to 32 Gb/s. It recovers clock signals from data streams when unavailable from the device under test, or cleans up clock signals degraded by excessive jitter. The module includes a 1:2 demultiplexer for sub-rate BERT testing and integrates with Keysight's J-BERT and ParBERT receiver test solutions.

Technical Specifications

• Data Rate Range: 50 Mb/s to 32 Gb/s; option extends to 16.5 Gb/s for standards including 16GFC, USB 3.0, SATA, SAS, and PCIe Gen4


• Phase-Locked Loop: Tunable loop bandwidth to 20 MHz with selectable peaking for industry standard compliance


• Jitter Performance: Auxiliary clock output with residual jitter as low as 100 fs RMS


• Demultiplexer: Built-in 1:2 demultiplexer with software-controlled, swappable outputs (even and odd bits)


• Data Input Connectors: 2.4 mm (f)


• Clock/Data Output Connectors: SMA


• Control Interface: USB for PC connection and graphical user interface

Key Features

• Clock recovery from data streams when DUT clock output is unavailable


• Phase-Locked Loop clean-up function for clocks with excessive intrinsic jitter


• Low residual jitter enables accurate transmitter measurements


• Software-controlled demultiplexer output selection simplifies receiver testing workflows

Typical Applications

• receiver and transmitter characterization


• High-speed device receiver testing with J-BERT and ParBERT solutions


• Golden PLL operation for stimulus-response testing with precision jitter sources (86100CU-400, 86100DU-400)


• Transmitter waveform analysis


• Computer, datacom, and communication standards validation

Compatibility & Integration

• Compatible with Keysight J-BERT (N4903B) and ParBERT receiver test solutions


• Integrates with 86100 Digital Communications Analyzer


• Configurable as jitter receiver for PLL stimulus-response testing with 86100CU-400 or 86100DU-400 software


• Integrates into multi-channel BERT systems including 81250 ParBERT for full-rate sampling to 27 Gb/s


• Cable kit N4915A-016 maintains phase relationship between recovered clock and demultiplexed data


• Compatible with pick-off kits such as N915A-015 (50 GHz bandwidth)